The present invention pertains generally to systems for processing envelopes and the like, and is more particularly directed to a conveyance means of a system for the automatic in-line printing, numbering, dating, collating and packaging of a substantially continuous flow of envelopes in the form of primary envelopes between which insert envelopes may be selectively disposed as the primary envelopes are conveyed along a predetermined path.
It is a conventional practice in many organizations, particularly church congregations, to provide envelopes to members in which regular donations or offerings may be made for financial support. In the case of church offerings, the envelopes used for offerings are generally of a smaller size than conventional letter size envelopes, approximately 3.25.times.6.25 inches and of rectangular shape. The front face of each envelope is commonly imprinted with the name of the church and frequently the particular purpose of the envelope, such as "Weekly Offering". A set of such envelopes is generally contained within a carton, with each envelope being serially numbered and dated to indicate the date on which the envelope is to be used. Frequently, one or more insert or special envelopes are intermixed in a selected date order with the main offertory envelopes so as to remind the church member of a particular church activity or special offering during the church year. The insert envelopes are included in the serial numbering sequence and may additionally include different indicia.
Traditionally, envelopes, such as offertory envelopes, which are to be packaged as primary envelopes in predetermined order in small individualized cartons have been prepared by printing the desired indicia on each envelope at a first operating station. Thereafter, a quantity of the printed primary envelopes are manually transported to a separate inserter station for either manual or mechanical insertion of special insert envelopes at selected positions between the primary envelopes. In accordance with known prior practices, the primary envelopes are printed with particular customer indicia, such as the name and/or logo of the organization, by means of a print cylinder as they are fed from a hopper onto a conveyance means for transfer to the inserter station. Prior to reaching the inserter station, the primary envelopes are further printed with the date on which the envelope is to be used, and a serial number common to each envelope in a given set. This requires that the insert envelopes be preprinted to indicate not only the particular event for which they are to be used, such as a Thanksgiving offering, but also the date of the corresponding event and a serial number matching the serial number printed on the primary envelopes making up the set into which the insert envelopes will be inserted. Thereafter, the envelopes are collated into sets and packaged into individualized cartons.
A significant drawback in the previous manner in which primary and insert envelopes, and the like, have heretofore been printed and collated is that should a particular job or "run" of envelopes be changed, such as by reducing the number of primary and insert envelopes which are to make up a given set, substantial waste is incurred due to the preprinted but unused insert envelopes. A further drawback is that the prior techniques have required relatively high labor intensity for the preprinting and insertion process which contributes significant expense to the effort of soliciting contributions from church members. Since the use of such offertory envelopes is widespread and entails substantial numbers of envelopes, it will be appreciated that significant cost reductions can be realized if the manufacturing process for them, i.e., printing primary envelopes, selectively inserting special insert envelopes between the primary envelopes, sequentially numbering and dating both, and collating and packaging the envelopes into individualized cartons, can be improved so as to reduce both the waste and the labor cost factor of prior methods.
A particularly advantageous apparatus is described in the referenced Cantile application to overcome these problems and provides an automatic high speed system for printing, numbering, dating, collating, and packaging a substantially continuous flow of envelopes in the form of primary envelopes between which insert envelopes can be selectively disposed as the primary envelopes are conveyed along a predetermined path. Generally, the conveyance means for moving the continuous stream of envelopes along the predetermined path is a chain driven pusher type linkage having spaces for each envelope between each set of upstanding pushers. An envelope, either a primary or insert, is delivered in between a set of the pushers and is propelled or pushed along in the continuous stream by motion of the linkage. While considerably more advanced than the prior systems, several reasons make the apparatus with the described conveyance means less advantageous than need be.
First, when the chain linkage is operated at high speeds, for example 25,000 to 40,000 envelopes/hr., the envelopes have a tendency to fly up and float off the linkage because of the lift caused by the air rushing over them at high speeds. This effect is particularly detrimental when it occurs near a printing station. In the aforementioned Cantile application, an ink jet print station is triggered by an edge detecting photocell and used to print at high speeds many of the serialized indicia used on the envelopes. If the envelopes are not substantially flat while being sprayed or ink jetted at the printing station, then misprints, hard to read indicia, poor quality printing, and the like are the result. The lifting effect increases with chain speed and tends to limit production rates if not overcome. It would be highly advantageous to operate the envelope processing apparatus described in Cantile without such effect.
Further, at head end of the conveyance means of the aforementioned system, a primary printing station prints indicia on the primary envelopes and then transfers them to the conveyance means for the inserting process and a second printing process. At high speeds with a continuous flow it is a delicate process to place or transfer an envelope correctly onto the linkage or pusher chain between a set of pushers. The envelope not only has to be placed with the correct timing spatially, but also in such a manner that it lays relatively flat so that it does not jam the conveyance means and the subsequent printing station is not presented with a registration problem. There also exists the opposite problem at the distal end of the conveyance means prior to a boxing and cartoning station, i.e., that of removing the high speed continuous flow of envelopes from between the pushers of the chain linkage.
The pusher type conveyance means is additionally somewhat inflexible because once the size of the envelope is selected, the distance between the the pushers is set. If it is desired to change the apparatus for processing a different size of envelope, then the entire conveyance chain must be changed to a different size and retimed. It is more desirable to have such a high speed piece of capital equipment flexible enough to be used for several different types of tasks and capable of handling similar stock in the same category.
Because the prior conveyance means is timed relatively closely in terms of the physical spacing of the envelopes, the machine is preferably run at a certain set speed and controlled off of one reference interrupt from a single shaft encoder for the feeder of the primary envelopes. With increasing speed or the number of inserts, such timing is problematic as errors in position or timing of the stream of envelopes tend to accumulate in an unpredictable manner. Further, the mechanical linkage can wear, introducing further imprecision into the timing. Such mechanical considerations have a tendency to limit the speeds at which such envelope processing apparatus can be run.